** Citigroup upgrades bitcoin miner Riot Platforms RIOT.O to "buy" from "hold"

** Says recent high performance computing (HPC)/AI activity, notably, Oracle's $300bn infrastructure partnership with OpenAI has prompted a rethink on the timing and value of RIOT's assets

** "We await end-of-month BTC metrics to finalize our 3Q estimates, though make changes to our SOTP framework, now assuming 400 MWs of approved/energized capacity valued at $12.4m/MW" - Citigroup

** Shares of RIOT up 2.3% at $18.10 premarket

** All of the 18 analysts covering RIOT rate the stock "buy" or higher; their median PT is $18- data compiled by LSEG

** As of last close, RIOT shares up 73.3% YTD

(Reporting by Anuj T in Bengaluru)

((anuj.t@thomsonreuters.com))